Certain Spartan Ops Chapters don't work.

To be more accurate, it throws me back to the title screen.
Out of the first 2 episodes I could only play 5 chapters.
I have tried deleting and reinstalling it various times but it still doesn’t work.
A friend of mine tried the same and it worked for him, so its definitly not the internet provider/connection.
I got and xbox elite with an HDD from the white xbox.
I’ve searched for a solution for this quite annoying problem which alot of people seem to encounter.
I wish for 343 to fix this problem as soon as they can or atleast give some information regarding what the problem is and what to do about it.

Kind regards

have you installed the first disc to the hard-drive, that may help. other than that i have no idea, try playing coop with friend or online.